Method of manufacturing electronic device

A method of manufacturing an electronic device, comprising:

• forming a first layer wiring made of aluminum or an aluminum alloy on the surface of a first layer insulating film on a substrate;
• forming a second layer insulating film on the first layer insulating film including the first layer wiring;
• subjecting the second layer insulating film to a reactive ion etching with a resist pattern used as a mask so as to form a via hole extending to reach the surface of the first layer wiring;
• treating the surface of the second layer insulating film including the via hole with an aqueous solution for removing the etching residue, the aqueous solution containing a peroxosulfate, a fluorine-containing compound and an acid for adjusting the pH value and having a pH value of −1 to 3;
• forming a conductive barrier layer on at least the inner surface of the via hole;
• forming a conductive material film on the surface of the second layer insulating film including the inner region of the via hole having the barrier layer formed on the inner surface;
• and
• removing the conductive material film and the conductive barrier layer by a chemical mechanical polishing so as to form a via fill.

A method of manufacturing an electronic device, comprising:

• forming a tungsten-based via fill in an insulating film on a substrate;
• forming a wiring material layer on the insulating film including the via fill;
• patterning the wiring material layer by a reactive ion etching with a resist pattern used as a mask so as to form a wiring having a smaller width in the contact portion with the via fill;
• and
• treating the surface of the insulating film including the wiring with an aqueous solution for removing the etching residue, the aqueous solution containing a peroxosulfate, a fluorine-containing compound and an acid for adjusting the pH value and having a pH value of −1 to 3.